The practice of dentistry utilizes a plurality of power driven tools for remediating decayed dental areas and for cleaning tooth surfaces. Traditional dental equipment is driven by an external drive device to cause the tool to rotate. The external drive device may be either a motor with an articulable power transmission, e.g. a pivoting pulley and belt system, a supply of compressed air that is directed to the dental handpiece through tubing, or an electric motor in the dental handpiece that is powered by an electrical cord. These three drive systems provide the needed power, but the connected hoses, pulleys and belts, or electrical cords cause them to be fairly cumbersome and fatiguing to use, particularly for extended periods of time, as is typically the case in professional cleaning of a patient's teeth.
Recent developments in dental equipment have provided certain advances in apparatus for the rotating of dental tools. These drive devices are substantially self-contained and free of a cumbersome external drive. These devices have a battery and a motor within the handpiece, thereby eliminating the cumbersome power transmission apparatus. The resultant cordless handpiece is more easily manipulated and, especially in use by a dentist or dental hygienist for long periods during dental cleanings, less likely to cause fatigue. However, the known devices are limited in the manner for controlling the power, i.e. switched on and off. The known cordless handpieces are controlled by a switch that is located in an inconvenient position. The switch on known devices is located either toward the rear of the handpiece or near the front of the handpiece. The dental hygienist must hold the handpiece with one hand and actuate the switch with the other hand, typically done before the dental tool is in the patient's mouth. When used for cleaning the patient's teeth, this results in much of the cleansing paste being sprayed outside of the mouth, which tends to be wasteful and messy. In addition, tooth cleaning is typically done with a series of short bursts of drive power, making the remotely located switch even more inconvenient. In order to rotate the dental tool at the forward end of the handpiece, the entire handpiece must be rotated. The present invention provides a unitary cordless dental drive apparatus that is an improvement on, and overcomes the drawbacks of, the known prior devices.